Blind stitch sewing machine



May 16, 1939. H. c. MbuL-roN E 2,158,246

BLIND STITCH SEWING MACHINE Fil ed April 14,1936 1o Shets-Sheet 1 //arley C MOI/Zion CharlesW/VueZZer May 16, 1939. H. c. MOULTON El A\L2,153,245

BLIND STITCH SEWING MACHINE May 16,1939. \H. c. MOULTON ET AL BLINDSTITCH SEWING MACHINE Filed April 14, 1936 10 Sheets-Sheet 4 awe/who e:

//A an 9 C. Mar/L TON Cf/A H 45.5 1% Man L 58 'May 16, 1939.. .H. MOULTN Em 2,158,246

B LIND STITCH SEWING MACHINE Filed April 1'4, 1936 10 Sheets-Sheet 5 2/7 9 z w M m i 11.

V zz/JW AQRLEY C. MOUL rb/v May 16, 1939- .H. c. MOUL'II'ON El AL BLINDSTITCH SEWING MACHINE Filed April 14, 1936.

$2 5 f O 56 Fl .2

10 Sheets-Sheet 6 HARLEY cZ/vouLro/v y- 1939- H. c. MVOULTON El AL2,158,246

BLIND STITCH SEWING MACHINE Filed April 14, 1956 lOSheets-Sheet 7 IT/lA/PL E) C. Moi/1.70M & C/m 21.53 W Nana's-R May 16, 1939. H. C.MOULTON ET AL 2,158,246

BL IND STITCH SEWING MACHINE Filed April 14, 1936 l0 Sheets-Sheet B HARLE) C. MOULTON @644 A; 3 14 MUEZLER May 16, 1939. )H. c. MOULTON ET AL2,158,246

" BLIND STITCH SEWING MACHINE Filed April 14, '1956 10 Sheets-Sheet 9 al EM.

May 16, 1939. H. c. MOULTON ET AL 2,158,246

a BLIND STITCH SEWING MACHINE Filed April 14, 1956 10 Sheets-Sheet 10zz'fL HAHLEr C. M004 ra/v CHAR E5 M1 MUELLER s: W ammo/I Patented May16, 1939 UNITED STATES PATENT OFFICE BLIND STITCH SEWING MACHINEApplication April 14,

6 Claims.

This invention relates to new and useful improvements in sewing-machines generally, although more particularly to those of the blindstitch type.

provide a novel means for driving the loop taker from the main shaftwhereby the'sewing zone will be spaced a considerable distance belowsaid main shaft to thereby provide a maximum of work clearance space.

With this and other objects in view which will more fully appear, thenature of the invention will be more clearly understood by following thedescription, the appended claims, and the several 15. views illustratedin the accompanying drawings.

The work support forms the subject matter of our copendi-ng applicationSerial No. 183,892, filed January '7, 1938. The sewing machine frameforms the subject matter of our copending application Serial No.196,972, filed March 19, 1938.

In the drawings:

Figure 1 is a plan view of a sewing machine embodying the invention. 7

Figure 2 is a front elevation, parts being broken away and in section.

Figure 3 is a vertical cross section taken on the line 3-3 on Figure 1.

Figure 4 is a vertical transverse section taken on the line 44 on Figure1.

Figure 5 is a vertical cross section taken on the line 5-5 on Figure 2,the work support being in the normal elevated position.

Figure 6 is a detail view similar to Figure 5. the work support beingshown depressed.

on the line 'l-'l on Figure 3.

Figure 8 is an inverted plan view of the work support.

Figure 9 is an enlarged detail sectional view taken on the line 9-9 onFigure 8.

Figure 10 is a detail inverted plan view illustrating means foradjusting the tension of the spring which resists depression of the worksupport.

Figure 11 is an inverted plan view of the base.

Figure 12 is an inverted plan view of the work support mounting bracketper se.

Figure 13 is a rear elevation of the standard and arm per se.

Figure 14 is an inverted plan view of the sewing head per se.

Figure 15 is a rear view of the tensioning unit and its mounting.

Figure 16 is a vertical section taken on the 55 line Iii-I6 on Figure 1.

The principal object of this invention is to Figure '7 is a verticaltransverse section taken 1936, Serial No. 74,362

Figure 17 is a fragmentary front elevation illustrating a knee-pressequipment for depressing the work support.

Figure 18 is an inverted plan view illustrating the mounting of theknee-press equipment.

Figure 19 is a detail perspective View of the knee-press rod and cranklever dismounted.

Figure 20 is a detail vertical cross section taken on the line 20-20 onFigure 18.

Like reference numerals designate corresponding parts throughout theseveral figures of the drawings.

In the practical development of our invention, we construct the machineof independently mountable and replaceable units. There is provided abase unit A, a standard and arm unit B, a forwardly extending arm orsewing head unit C, a work support mounting bracket unit D, and a worksupport unit E. We also provide a removable thread tensioning unit Fwhich is preferably supported on the sewing head unit C.

The base unit A is in the nature of a generally rectangular flanged body5 having ,apertured, mounting lugs 6 by which the base may be securedupon a bench or table, and a rectangular opening 1 disposed at the pointat which the. standard and arm unit B is to be mounted on the base anddefined by apertured corner lugs 8 by which the mounting of the standardand arm unit is facilitated.

The base unit A is provided with a front cutout or recess 9 flanged byreinforce lugs l0 having formed therein horizontally alined bearingbores. A bearing lug H is provided for facilitating the mounting oftoggle links later to be referred to, and a clearance groove or recessI2 is provided for accommodating movement of the devices by which thetoggle links are actuated. Another bearing lug I3 is provided forsupporting a tension adjusting bar which cooperates with the togglepositioning devices.

The standard and arm unit B includes a standard portion [4 and anoverhanging arm portion I 5, the former being provided at its lower endwith a rectangular opening matching the opening I in the base anddefined by tapped corner lugs l6 for receiving the screws l1 by whichthe base unit A and the unit B are secured together in assembledrelation as shown in Figures 3 and 4 of the drawings. The standardportion I4 is provided with a front opening l8 which is covered by aremovably mounted plate I9 which is slotted for a purpose that willlater become apparent.

The overhanging arm portion I5 is provided with the usual main shaftbearings in which the main shaft 2| is journaled, said shaft beingequipped with the usual pulley wheel 22.

At its free end the arm |5 carries a mounting flange 23 through themedium of which the forwardly extending arm or sewing head unit C isremovably mounted on said arm, and a centering sleeve boss 24 forfacilitating the mounting of said unit C in proper relation upon thearm. The boss 24 is interrupted or cut out at one point as at 25 for apurpose that will be described later.

Within the arm the main shaft 2| carries an eccentric 26 and collar 21,the eccentric being connected by strap 28 and pitman 29 with one end ofa bell crank lever 30 pivotally mounted on the shaft 3| supported asillustrated in Figure 3 in bearings provided therefor in the walls ofthe standard M. The remaining arm of the bell crank has connectedthereto a link 32 which projects through and works in the slot of thestandard cover plate IQ for a purpose that will be described later.

The sewing head unit C carries the mechanism by which the stitches areformed. In this particular disclosure the machine is adapted for theformation of single thread chain stitches but it is to be understoodthat the invention is not limited to this specific form of stitchforming mechanism. The unit C includes a head casting 33 having flangeextensions 34 adapted to be removably secured, through the medium of thescrews 35, to the mounting flange 23 with which the standard and armunit Bis equipped.

The casting 33 is provided with a recess or bore 36 for snugly receivingor fitting upon the sleeve boss 24 extending from the overhanging arml5. It will be observed by reference to Figures 2 and. 3 of the drawingsthat the main shaft 2| projects into the interior of the casting 33.

The casting 33 is provided with an opening 31 which is located inalinement with the main shaft 2 I, and through which access may be hadto certain transmission elements connected. to the adjacent end of themain shaft. This opening is covered by a removable thread tensioningunit F as illustrated in Figures 2, 3, and 15. The unit F comprises aplate 38 of a size adapted to overlie and cover the opening 31. A post39, which is attached to the plate 38, projects outwardly therefrom andcarries thread tension discs 40. A thread guide 4| is clamped betweenthe post and the plate. A flange lug: 42 which is rigidly attached tothe inner face of the plate 38 adjacent one side edge thereof throughthe medium of a bracket 42, cooperates with said side edge to receivetherebetween the associated side edge of the opening 31. A latch 43 inthe form of a bell crank lever is pivoted as at 44 to the inner face ofthe plate adjacent the other side edge thereof. This lever includes ahorizontal arm which projects towards the lug 42 and a depending arm.

which terminates in a lug 45 adapted to overlie the adjacent side edgeof the opening 31. A coil spring 46 is connected at one end to thehorizontal arm of the lever 43 and at its other end. to the bracket 42,and functions to urge the latching lug 45 outwardly. The outwardmovement of the lug 45 is limited by a stop 43*, which is attached tothe bracket 42*, and is normally engaged by the horizontal arm of thelever 43, as shown in Figure 15. In order to remove the unit F, it isonly necessary to move the same laterally until the lug 42 is free ofthe adjacent side edge of the opening 31 and then swing the unitoutwardly. When replacing the unit, the

latch lug 45 is first engaged with the associated side edge of theopening 31, the unit moved laterally against the tension of the spring46 until the lug 42 becomes seated in the opening, and upon release ofthe unit the latter will slide laterally in the opposite directionthrough the medium of the spring 46 until the lug 42 has been positionedin latched relation with the associated side edge of the opening.

The casting 33 is provided with front and rear bearings 41, 48 in whichis rockably mounted a needle shaft 50. It will be observed by referenceto Figures 1, 2 and '7 of the drawings that the needle shaft is disposedin the line of feed of the work or in right angular relation to the mainshaft 2 I, and that its axis is disposed a considerable distance belowthat of the main shaft, as shown in Figure 2.

A stationary presser foot 5| is rigidly mounted on the forward end ofthe arm or casting 33 below the. needle shaft 50 and is provided with alongitudinal opening 52 in which a top feed dog operates and throughwhich a node of fabric is raised by a ridge-forming element in the usualmanner The needle shaft 50 projects forwardly through the front end ofthe arm or casting 33 and has secured thereon a needle arm 53 to which aneedle 54 is affixed and by which said needle is oscillated back andforth in a plane at right angles to the direction of feed of the work,or, in other words, in a plane parallel to the plane in which the axisof the main shaft lies. At its inner or rear end the needle shaftcarries a crank 55 which is connected by a pitman 56 to an eccentric 51secured upon the end of the main shaft 2| which projects into the arm orcasting 33 as shown in Figures 3 and 7 of the drawings.

A 4-motion top feed dog 58 is removably secured as at 59 to the forwardend of a feed bar 60. In order to impart to the dog 58 the desiredlifting and lowering movements, the bar 60 is provided with a camgrooveway 6| into which a fixedly supported roller 62 projects, theroller being journaled on a pin which is adjustably supported as at 63in a wall of the casting or arm 33, as shown in Figure 4 of thedrawings.

In order to impart the feed travel movement to the feed bar 60, weprovide an eccentric 64 which is encircled by a strap extension 65 ofsaid arm and is fixed to and is rotatable with a stub shaft 66 having abearing at one end in a cap 61 removably secured at 68 to the casting 33and having its other end journaled in a bearing 69 formed in a rear armextension 10 of the web 49.

Also fixed to the stub shaft 66 is a drunken cam H having a thrust rodconnection as at 12 with a looper 13. The thrust rod slides in a ballbearing 14 supported by an arm 15 which is pivotally mounted upon aneccentrically adjustable pin 16 whereby the position in space of theball bearing 14 may be varied to suit the demands of operation of thelooper.

A spur gear 11 and a mounting collar on which the gear is removablymounted are removably secured upon the main shaft, the gear operatingwithin and protected by the sleeve boss 24, as shown in Figure 3. Thegear 11 meshes with an intermediate idler gear 18 having a ball bearingmounting as at 79 on a stud pin 80 removably secured as at 8| to theflange 23 carried by the standard and arm unit B. The cutout portion 25of the sleeve boss 24 permits the gears 71 and 18 to mesh, and thecasting 33 is provided with an opening 82 of sufiicient size to permitcooperation of said gears.

The intermediate gear I8 imparts rotary motion form the main shaft 2| toa gear 83 secured upon the stub shaft 66 upon which the eccentric 54 andthe drunken cam II are mounted.

A spring pressed finger 84 is pivoted on the presser foot and projectsinto the longitudinal slot 52 to hold the fabric stationaryduring thereturn movement of the disc.

The casting 33 is open at the bottom, the left side and the rear, and ispartially closed by a housing cap 85 which is removably secured by ascrew 86 to the web 49. The cap 85 includes a rear recess which isclosed by a removable plate 81.

The work support mounting bracket unit D comprises a body 88 which isremovably secured upon the base unit by screws 89, and the body has araised, hollow housing portion 90 which is open at the front, andforwardly extending arms 9| each carrying a bearing 92. In these spacedbearings a pivot shaft 93 is secured, and on this shaft the work supportunit E-is pivotally mounted to swing downwardly and rearwardly. The unitE is equipped with a cone seat bearing 94 to receive the conical end 95of the shaft 93. The other end of the shaft 93 is equipped with aconical seat 96 to receive the conical end of a bearing screw 91 whichis mounted for projection and retraction in a screw bearing 98 providedin the unit E, as shown in Figure 2 of the drawings.

It will be noted that the work support unit E. is pivotally mountedalong a line paralleling the main shaft 2I and at a point well inadvance of the stitch forming zone. In this manner a relatively largeclearance between the work support and the presser foot is provided forby a relatively small amount of depression of the work support.

The work support unit E is provided with a lateral extension 99underlying the presser foot and at its end this extension supports apivotally and yieldably mounted work clamp I00 which cooperates with thepresser foot.

The work support unit E also carries a ridgeforming element liiI whichin this particular disclosure is in the form of an oscillatory disc. Thedisc is disposed beneath the longitudinal slot 52 in the presser footand is fixed to a rock shaft I02 supported in bearings I03 provided inthe unit E and arranged in parallelism with the main shaft 2|.Oscillatory movement is imparted to the shaft I02 and the disc I9Ithrough the medium of a crank I04 secured upon said shaft and havingconnection with the link 32 which is actuated from the main shaft 2| inthe manner hereinbefore described. Depression of the work support isnormally opposed by a strong spring designed to permit a yieldingmovement of the work support away from the presser foot to adapt themachine to operate upon materials of uneven thickness. It is desirablethat the operator should not be subjected to the strain incident todepressing the work support against the tension of the heavy spring andfor this reason we have provided means for disabling the heavy springwhen it is. desired to depress the work support for inserting orremoving the work. For this purpose the work support unit E is providedwith a cup-socket I05 in which operates a vertically movable plunger orsupport I05 opposed by a heavy coil spring I01 mounted in said socketand providing said strong spring resistance. A reduced portion I08 ofthe plunger or support I05 extends through an aperture in the worksupport and carries an enlarged head. I09 which operates in a recessformed in the work support and serves to limit the upward movement ofthe work support E relative to the plunger or support I06 and therebyinitially set the work support relative to the presser foot.

The plunger I06 is pivotally connected to the upper one of a pair ofupper and lower toggle links IIO which are pivotally connected asillustrated in Figures 5 and 6 of the drawings, and the lower link ofwhich is pivoted as at I I I between the reinforce lugs I0 with whichthe base unit A is provided. When the toggle links H0 are in verticalalinement with the lower pivot III and the plunger I06, the latter islocked and consequently the work support E is locked against fulldepression, but the work support however is capable of being slightlydepressed against the tension of the spring I01 to permit differentthicknesses of fabrics and seams passing under the presser foot. Anoperating link H2 is pivotally connected to the lower toggle link and isreciprocable back and forth within the raised, hollow housing portion 90of the bracket body by reason of movement of the bell crank lever H3 toone arm of which said operating link is connected. The bell crank leverH3 is pivoted as at M4 to the base lug II and has its remaining armconnected by a chain or otherwise to a foot treadle not shown). It willbe readily seen by reference to Figures 5 and 6 of the drawings that bypullingand at its other end to an adjustable anchor bar Ill. The bar II!is pivotally supported at II8 intermediate its ends on the base lug I3.An adjustable screw I I 9 engages the other end of the bar II! and bythis means the tension of the spring II2 may be adjusted. An adjustablestop screw I20 is carried by the lower toggle link I I0 in position forengaging the adjacent wall of the base recess 9 for limiting themovement of the toggle links in the normal relation of the partsillustrated in Figure 5 against the tension of the spring IIB.

Inorder to vary the spaced relation between the needle and the ridgeforming element, we provide a bell crank lever i2! which is pivotallysupported upon the pivot shaft 93 and which includes a dependingsubstantially vertical arm and a substantially horizontal and rearwardlyextended arm. The vertical arm carries an adjustable stop screw I22which is engageable with a stop lug on the bracket unit D fordetermining the position of the work support as indicated in Figure 5 ofthe drawings. An adjustment lever I23 is pivotally supportedintermediate its ends as at I24 in a bifurcation or slotway formed inthe rearwardly extended end of the horizontal arm of the bell crank I2I,and the rear end of the lever I23 overlies and engages a shelf memberI25 which is removably secured to the rear edge of the work support asillustrated in Figs. 5 and 6 of the drawings. The front end of the leverI23 overlies an end of an adjuster bar I25 which is pivoted intermediateits ends as at I2? upon a lug extending laterally from the horizontalportion of the bell crank lever I2 I. The remaining end of the adjusterbar is engaged by an adjuster screw I29 which extends downwardly througha threaded bore provided therefor in the work support E. The worksupport E is equipped with a recess or well I30 for accommodating theoperating knob I 3I with which the screw I29 is equipped and through themedium of which the screw may be adjusted for depressing to a greater orlesser extent the end of the adjuster bar I26 with which the screwscontact.

It will be readily understood that by turning the knob I3I so as to movethe screw downwardly, the bar I26 will be actuated to exert an upwardpressure on the forward end of the adjustment lever I23 causing the rearend thereof to be depressed against the shelf member !25 to increase thespace between the needle. and the ridge forming element and therebyreduce the depth of needle penetration in the fabric. Obviously amovement of the knob I3I in the opposite direction will serve todiminish the space within the limit determined by the limiting head N18to thereby increase the depth of needle penetration in the fabrics. Alight coil spring I32 connected between the front edge of the worksupport and the vertical arm of the bell crank lever I2I as shown inFigures 5 and 6 of the drawings serves at all times to hold the shelfI25, lever I23, bar I26, and screw I29 in mutual contact.

The adjustment lever I23 pivotally supported in a bifurcation in andextended from the rear end of the horizontal bell crank lever arm, formsa longitudinal extension of that arm and by adjustment of the positionof the lever the effective angular relation of the arms of the bellcrank is varied. Thus by reason of the contact of the vertical arm withthe stop lug on the bracket unit D, and the horizontal arm and itsadjustable lever extension with the work support shelf I25 the varyingof the effective angular relation of the bell crank arms will vary thespaced relation between the presser foot and the work support.

If desired, a knee-press may be substituted for the treadle and chainequipment H5 and utilized for effecting depression of the work supportE. See Figures 1'7, 18, 19 and 20. The kneepress includes a crank rodI133 to the vertical leg of which is adjustably afiixed a knee-pressplate I34. The horizontal leg I35 of the rod is pivotally supported inbearings I36 on the base unit A and carries a rigidly affixed cranklever I31, the cam end I38 of which overlies the horizontal leg of thebell crank lever II3 as shown in Figures 18 and 20.

By forcing the knee-press plate I34 to the right, or as shown by thearrow in Figure 17, the crank lever I31 will be depressed and the camportion I38 thereof will press downwardly upon the horizontal arm of thebell crank lever H3 and impart thereto the same work support depressingmovement as would be imparted by use of the chain II5 hereinbeforedescribed.

In the foregoing description we have disclosed a machine composed of aplurality of individually mountable and replaceable standardized units,namely, a base unit, a standard and arm unit, a forwardly extending armor sewing head unit, a mounting bracket unit, and a work support unit.

By reason of the construction and mounting of the particular worksupport disclosed and the arrangement of the driving connections in thesewing head, a maximum of feeding room is provided beneath theoverhanging arm and the sewing head. This feature of the machine isgreatly aided by the provision of the triple drive gear arrangement inthe sewing head including the intermediate gear I8 removably carried bythe mounting flange of the standard and arm unit B. As previouslystated, the driven gear 83 is carried by the sewing head and the drivergear IT is removably carried by the main shaft 2I and protected by thesleeve boss 24 of the standard and arm unit B.

It is of course to be understood that the details of structure andarrangement of parts may be variously changed and modified without departing from the spirit and scope of our invention.

We claim:

1. In a sewing machine, work feeding means, a main shaft disposedtransversely of the direc tion of feed of the work, complementary stitchforming means including a reciprocatory needle and a loop taker, aneedle drive shaft disposed in right angular relation to the main shaft,means for imparting movement from the main shaft to the needle shaft, awork support extending beneath the stitch forming means, and means fordriving the loop taker from the main shaft including intermediategearing serving to space the sewing zone a considerable distance belowthe main shaft whereby to provide a maximum of work clearance space.

2. In a sewing machine, work feeding means, a main shaft disposedtransversely of the direction of feed of the work, complementary stitchforming means including a reciprocatory needle and a loop taker, aneedle drive shaft disposed in right angular relation to the main shaft,means for imparting movement from the main shaft to the needle shaft, awork support extending beneath the stitch forming means, said worksupport being tiltable about an axis disposed parallel with the axis ofthe main shaft and spaced a considerable distance in advance of thepoint at which the stitch forming occurs, and means for driving the looptaker from the main shaft including intermediate gearing serving tospace the sewing zone a considerable distance below the main shaftwhereby to provide a maximum of work clearance space.

3. In a sewing machine wherein is provided a frame including anoverhanging arm and a sewing head supported on the arm, a main shaftrotatably supported in the arm, complementary stitch forming meansincluding a loop taker, and a train of transmission gearing located inthe head for imparting movement to the loop taker from the main shaftand serving to space the point at which the stitch forming occurs aconsiderable distance below the arm to provide for a maximum of workclearance.

4. In a sewing machine wherein is provided a frame including anoverhanging arm, a main shaft rotatably supported in the arm, a sleeveboss extending longitudinally from said arm, a driver gear secured onthe main shaft and rotatable within the boss, a sewing head removablysupported on said arm and into which the gear bearing end of the mainshaft projects, complementary stitch forming mechanism supported in partin said head and including a loop taker, a stub shaft rotatablysupported in the head and having driving connection with the loop taker,and a train of gearing connecting the main shaft gear with the stubshaft.

5. In a sewing machine wherein is provided a frame including anoverhanging arm, a main shaft rotatably supported in the arm, a. sleeve2,158,246 5 boss extending longitudinally from said arm,a a driver gearsecured on the main shaft and rodriver gear secured on the main shaftand rotatable within the boss, a sewing head, mounting flanges carriedrespectively by the arm and the head enabling the latter to be removablyse'curd upon the former, an end of the main shaft being projected intosaid head, complementary stitch forming means carried in part by thehead and including a loop taker and a stub shaft rotatably supported inthe head and having driving connection with the loop taker, a drivengear secured on the stub shaft, and an intermediate gear meshing withthe driver and driven gears and carried by the arm supported mountingflange.

6. In a sewing machine wherein is provided a frame including anoverhanging arm, a main shaft rotatably supported in the arm, a sleeveboss extending longitudinally from said arm,

tatable within the boss, a sewing head, mounting flanges carriedrespectively by the arm and the head enabling the latter to be removablysecured upon the former, an end of the main shaft being projected intosaid head, complementary stitch forming means carried in part by thehead and including a loop taker and a stub shaft rotatably supported inthe head and having driving connection Withthe loop taker, a driven gearsecured on the stub shaft, and an intermediate gear meshing with thedriver and driven gears and carried by the arm supported mountingflange, said boss and said head carried mounting flange having cut outportions for accommodating the positioning and operation of said gears.

CHARLES W. MUELLER. HARLEY C. MOULTON.

